Diagnostic System Check

Circuit Description
The ignition switch supplies Ignition 1 voltage to the Inflatable Restraint Sensing and Diagnostic Module (SDM) at terminal 10 using the SIR Fuse. When the ignition switch is first turned to the RUN position, the SDM responds by flashing the AIR BAG warning lamp 7 times, then turning the AIR BAG warning lamp to the OFF position while performing tests on the SIR system.

Diagnostic Aids
You must diagnose the diagnostic trouble codes in the order specified by the A Diagnostic System Check-SIR. Failure to do so may result in the following problems:
^ Extended diagnostic time
^ Incorrect diagnosis
^ Incorrect parts replacement

Test Description
Refer to step numbers on the diagnostic table.
2. The Inflatable Restraint Instrument Panel (IP) Module switch must be in the ON position in order to perform the Diagnostic System Check.
3. The AIR BAG warning lamp should flash 7 times after the ignition switch is first turned to the RUN position.
4. The AIR BAG warning lamp indicates improper operation. This test differentiates a Warning Lamp Stays ON condition from a Warning Lamp Does Not Come ON condition.
5. The AIR BAG warning lamp should turn OFF after flashing 7 times.
6. This test inspects for the proper operation of the serial data line.
8. This test identifies the stored diagnostic trouble codes (DTCs) and whether they are current or history.
10. This test inspects for the proper operation of the serial data line.
11. This test refers to the appropriate DTC Diagnostic Aids table for diagnosis of the history DTCs.